The Daley family played no role in the 2004 death investigation involving the mayor's nephew, but Chicago police and prosecutor response did, according to a special report.

February 4, 2014 5:15:45 PM PST

February 4, 2014 (CHICAGO) --

A special prosecutor determined there was no evidence former Chicago Mayor Richard M. Daley, his family or others engaged in conduct to influence the death investigation of David Koschman, who died after an altercation with Daley's nephew, Richard ''RJ'' Vanecko, in 2004.

The report, released on Tuesday, indicates Mayor Daley, eight relatives and 14 members of the mayoral staff and security detail were interviewed during the investigation. Special prosecutor Dan Webb concluded there was "no evidence that former Mayor Daley, his family, or others at their direction engaged in conduct to influence or attempted to influence the investigations." Read the 169-page report | Special prosecutor Press Release

However, the report finds that police did not go interview Vanecko even though he threw the punch that ultimately took the life of Koschman almost 10 years ago. According to police reports, the CPD didn't know Vanecko was involved in the death until 18 days after the altercation outside a Division Street bar.

Special Prosecutor Dan Webb's detailed report said Mayor Daley knew of his nephew's involvement shortly after the incident occurred in late April 2004. A violent crimes lieutenant recalled a conversation with a police higher-up in which the words, "Holy crap, maybe the mayor's nephew is involved" were used.

"In this city, then and now you don't need a phone call. You don't need a memo. When it's Daley, it's Holy crap, what do we do?" G. Flint Taylor, Koschman family attorney, said.

The Webb report lays out numerous actions by police and prosecutors during two investigations that are, at the very least, questionable. They included: witnesses that weren't interviewed; homicide reports that were lost; and detectives who edited a report to make it appear that David Koschman was the aggressor. That manufactured line was "F--- you, I'll kick your ass." No witness ever reported Koschman saying that to the much taller Vanecko

"What happened here was an investigation that was treated as a political football from day 1," Locke Bowman, Koschman family attorney, said.

The special prosecutor has determined that the conduct of police and prosecutors did not reach the threshold of criminality or it was prevented by statute of limitations. From what he found, Webb writes,"... the public could well conclude that the entire claim of self-defense came not from Vanecko, but rather, was conjured up in the minds of law enforcement."

Koschman's mom has long said she's wanted an explanation and an apology. Her attorneys said police and prosecutors owe her that much.

"An apology is the very least the Chicago Police Department could offer Nancy Koschman at this time," Locke Bowman, Koschman family attorney, said. Koschman's attorneys said they are exploring the possiblity of civil action at this time.

Last Friday, Vanecko apologized to Koschman's mother as he entered a plea deal in the case. He pleaded guilty to involuntary manslaughter last week in Koschman's death in exchange for 60 days in jail, 30 months of probation and an apology to Koschman's mother.

After that plea deal, special prosecutor Dan Webb said he would ask the judge to release the report in the Grand Jury investigation, which was launched in 2012. No charges were brought against Vanecko originally.